task-estimation

Task Estimation

When to use this skill

Sprint Planning: Decide what work to include in the sprint
Roadmap creation: Build long-term plans
Resource planning: Estimate team size and schedule

Instructions

Step 1: Story Points (relative estimation)

Fibonacci sequence: 1, 2, 3, 5, 8, 13, 21

Story Point guidelines

1 Point (Very Small)

Example: text change, constant value update
Time: 1-2 hours
Complexity: very low
Risk: none

2 Points (Small)

Example: simple bug fix, add logging
Time: 2-4 hours
Complexity: low
Risk: low

3 Points (Medium)

Example: simple CRUD API endpoint
Time: 4-8 hours
Complexity: medium
Risk: low

5 Points (Medium-Large)

Example: complex form implementation, auth middleware
Time: 1-2 days
Complexity: medium
Risk: medium

8 Points (Large)

Example: new feature (frontend + backend)
Time: 2-3 days
Complexity: high
Risk: medium

13 Points (Very Large)

Example: payment system integration
Time: 1 week
Complexity: very high
Risk: high
Recommended: Split into smaller tasks

21+ Points (Epic)

Required: Must be split into smaller stories

Step 2: Planning Poker

Process:

Product Owner explains the story
Team asks questions
Everyone picks a card (1, 2, 3, 5, 8, 13)
Reveal simultaneously
Explain highest/lowest scores
Re-vote
Reach consensus

Example:

Story: "Users can upload a profile photo"

Member A: 3 points (simple frontend) Member B: 5 points (image resizing needed) Member C: 8 points (S3 upload, security considerations)

Discussion:

Use an image processing library
S3 is already set up
File size validation needed

Re-vote → consensus on 5 points

Step 3: T-Shirt Sizing (quick estimation)

T-Shirt sizes

XS: 1-2 Story Points (within 1 hour)
S: 2-3 Story Points (half day)
M: 5 Story Points (1-2 days)
L: 8 Story Points (1 week)
XL: 13+ Story Points (needs splitting)

When to use:

Initial backlog grooming
Rough roadmap planning
Quick prioritization

Step 4: Consider risk and uncertainty

Estimation adjustment:

interface TaskEstimate { baseEstimate: number; // base estimate risk: 'low' | 'medium' | 'high'; uncertainty: number; // 0-1 finalEstimate: number; // adjusted estimate }

function adjustEstimate(estimate: TaskEstimate): number { let buffer = 1.0;

// risk buffer if (estimate.risk === 'medium') buffer *= 1.3; if (estimate.risk === 'high') buffer *= 1.5;

// uncertainty buffer buffer *= (1 + estimate.uncertainty);

return Math.ceil(estimate.baseEstimate * buffer); }

// Example const task = { baseEstimate: 5, risk: 'medium', uncertainty: 0.2 // 20% uncertainty };

const final = adjustEstimate(task); // 5 * 1.3 * 1.2 = 7.8 → 8 points

Output format

Estimation document template

Task: [Task Name]

Description

[work description]

Acceptance Criteria

Criterion 1
Criterion 2
Criterion 3

Estimation

Story Points: 5
T-Shirt Size: M
Estimated Time: 1-2 days

Breakdown

Frontend UI: 2 points
API Endpoint: 2 points
Testing: 1 point

Risks

Uncertain API response time (medium risk)
External library dependency (low risk)

Dependencies

User authentication must be completed first

Notes

Need to discuss design with UX team

Constraints

Required rules (MUST)

Relative estimation: Relative complexity instead of absolute time
Team consensus: Agreement from the whole team, not individuals
Use historical data: Plan based on velocity

Prohibited (MUST NOT)

Pressuring individuals: Estimates are not promises
Overly granular estimation: Split anything 13+ points
Turning estimates into deadlines: estimate ≠ commitment

Best practices

Break Down: Split big work into smaller pieces
Reference Stories: Reference similar past work
Include buffer: Prepare for the unexpected

References

Scrum Guide
Planning Poker
Story Points

Metadata

Version

Current version: 1.0.0
Last updated: 2025-01-01
Compatible platforms: Claude, ChatGPT, Gemini